1. That the letter inserted should be a consonant is evident. The vowel e (in numerus) had been previously ejected.
2. That it should be a mute is evident. A liquid would have given the unstable or unpronounceable combinations mnr, mlr, mrr, mmr.
3. That it should be a consonant, either of series b or of series s, was natural; it being series b and series s with which m and r are respectively connected.
4. That it should be a consonant of series b, rather than one of series s, we collect from the fact that msr (numsrus) or mzr (numzrus) give inharmonious, and, consequently, unstable combinations.
5. That of the b series, it should be b or v (flat) rather than p or f (sharp), we infer from the fact of m and r both being flat.
6. Of v and b, the latter alone gives a stable combination, so that we have the Spanish form nombre, and not nomvre.
In this we have an illustration of the use of attending to the nature and connections of articulate sounds in general.
[§ 226]. The affinity of m for the series b, of n for the series t, gives occasion to further euphonic changes. The combinations mt, md, mþ, mð, are unstable. The syllables emt, emd, are liable to one of two modifications. Either p or b will be inserted, and so make them empt (as in tempt), embd (as in Embden), or else the m will become n, forming the syllable ent, end, enþ, enð.
Similar tendencies, in a certain degree, affect the combinations enp, enb. They are liable to become emp, or emb. Any one may see that the word enperor embarrasses the utterance.